This is the default mode. In this mode the camera movement is locked to a focus object, which can be selected by double clicking or by using the find dialog (Ctrl+F).
There are two extra options available. These can be activated using the checkboxes at the bottom of the Camera panel in the GUI Controls window:

Lock camera to object – If this is activated, the relative position of the camera with respect to the focus object is maintained. Otherwise, the camera position does not change.

Lock orientation – If this is activated, the camera will rotate with the object to keep the same perspective of it at all times.

In this mode you take control of a spacecraft. In the spacecraft mode, the GUI changes completely. The Options window disappears and
a new user interface is shown in its place at the bottm left of the screen.

Attitude indicator – It is shown as a ball with the horizon and other marks. It represents the current orientation of the spacecraft with respect to the equatorial system.

– Indicates the direction the spacecraft is currently headed to.

– Indicates direction of the current velocity vector, if any.

– Indicates inverse direction of the current velocity vector, if any.

Engine Power – Current power of the engine. It is a multiplier in steps of powers of ten. Low engine power levels allow for Solar System or planetary travel, whereas high engine power levels are suitable for galactic and intergalactic exploration. Increase the power clicking on and decrease it clicking on .

– Stabilises the yaw, pitch and roll angles. If rotation is applied during the stabilisation, the stabilisation is cancelled.

– Stops the spacecraft until its velocity with respect to the Sun is 0. If thrust is applied during the stopping, the stopping is cancelled.

– Return to the focus mode.

Additionally, it is possible to adjust three more parameters:

Responsiveness – This slider controls how fast the spacecraft reacts to the user’s yaw/pitch/roll commands. It could be seen as the power of the thrusters.

Drag – This slider controls the friction force applied to all the forces acting on the spacecraft (engine force, yaw, pitch, and roll). Set it to zero for a real zero G simulation.

Force velocity to heading direction – This checkbox, when checked, makes the spacecraft to always move in the direction it is facing, instead of using the regular momentum-based motion. Even though physically inaccurate, this makes it much easier to control and arguably more fun to play with.